1. Field of the Invention
The present invention relates to processing for detecting a vertebra or vertebrae, and particularly to a vertebra center detection apparatus and method that is appropriate for automatically detection of the center of the vertebra or vertebrae in medical images. Further, the present invention relates to a recording medium stored therein a program for the apparatus and the method.
2. Description of the Related Art
Conventionally, automatic calculation of the center line of vertebrae based on a plurality of medical images that have been obtained by scanning a subject at a plurality of slice positions from the chest to the groins of the subject has been an essential technique in medical fields. Such an automatic calculation technique is indispensable to produce a vertebra CPR (Curved Planar Reconstruction) image to diagnose a compression fracture and to calculate the curvature of the vertebrae.
Therefore, processing for automatically detecting the center line of vertebrae in a plurality of medical images is performed by using a computer. For example, a technique for calculating the center line of the vertebrae by detecting the edge of the vertebrae in the medical images is proposed in U.S. Pat. No. 7,231,073.
However, the conventional techniques had problems that the vertebra detection performance (accuracy in detection of a vertebra or vertebrae) does not improve, because the shapes of structures in the medical images vary according to slice positions and an edge is generated by a structure in the vicinity of the vertebra. The shapes of the structures in the medical images vary, because the structures, such as ribs and clavicles, have different anatomical characteristics from each other.
Further, there has been a problem that when a subject has a lesion, such as osteoporosis and hyperostosis, if information about the edge of the structure is used alone, it is impossible to stably detect the vertebrae.